Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 13 of 13 for “"Environmental barrier"”.
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Degradation and Failure Analysis of Environmental Barrier Coatings under Adverse Operating Environment: Multi-Physics Modelling
Environmental barrier coatings (EBCs) are essential for protecting ceramic matrix composite (CMC) substrates in advanced gas turbines and aero-engines. However, their durability is limited by thermo-mechanical stresses, oxidation, and water-vapor-induced degradation under high-temperature operating …
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Structural and Thermal Properties of Ignition Resistant Coatings for Reusable Rocket Engines
This thesis relates my investigation of an environmental barrier coating formulation, first developed for Russian RD-180 engines, which prevents ignition due to particle impact on ox-turbopump turbine. Ignition resistant environmental barrier coatings are of particular interest for reusable rocket …
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Geopolymer-derived ceramics and composites
… goal of designing new candidate materials for environmental barrier applications. The materials were studied with in situ high temperature synchrotron X-ray diffraction to explore the atomic mechanisms responsible for the thermal evolution of these compounds. The framework distortions …
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Oxidation driven degradation of silicon nitride based hot surface ignition assistant devices
… attacks from oxidative species. A mullite-based environmental barrier coating was applied on some of the Bosch and Beru samples. While the mullite coating was able to protect a Bosch glow plug sample from oxidation in a pressurized wet oxygen environment, repeated testing is required to fully …
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Safety of light water reactor fuel with silicon carbide cladding
… strength. This, along with the presence of the environmental barrier coating around the load carrying intermediate layer of SiC fiber composite, diminishes the importance of oxidation for cladding failure mechanisms. Thermal shock experiments showed strength retention for both [alpha]-SiC and …
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Nonlinear Fluid-Structure Interaction in a Flexible Shelter under Blast Loading
… with a pressurized liner inside the tent as an environmental barrier. Field tests showed unexpected damage to the liner, and most of the damage occurred on tent's leeward side. To solve this problem, various tests and analyses have been performed, involving material characteristics of the liner, …
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Ecological Niches, Species Distributions, And Biogeographic Processes In Rodents On Neotropical Sky Islands
… to surmount the challenge of incorporating environmental information from the margins of species geographic ranges into ENMs. In so doing, I argue how populations that exist on the borders of species' local ranges (spatial margins) can lead to exaggerated estimates of their niches and …
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Polymer-derived Si-al-c-n Ceramics:oxidation, Hot-corrosion, And Structural Evolution
… find many high temperature applications such as environmental barrier coatings, ceramic matrix composites, and MEMS for harsh environments.
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Behavior of triplex silicon carbide fuel cladding designs tested under simulated PWR conditions
… monolith, a central composite, and an outer environmental barrier coating (EBC). The inner monolith consists of dense SiC which provides strength and hermeticity to contain fission products. The composite layer is made of SiC fibers, woven around the monolith, and then infiltrated with a SiC …
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The Adhesion Strength of a Plasma Sprayed Silicon Bond Coating on a Silicon Carbide Ceramic Matrix Composite
… components in next generation turbine engines. Environmental barrier coatings (EBCs) are essential for implementing these components as they insulate and protect the substrate from reaction with water vapor in the engine environment. EBCs are typically deposited via atmospheric plasma spraying …
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Exploration and Development of Methodology for Accessibility Assessments: Based on the Notion of Person-Environment Fit
… different functional capacity. Sixty-one core environmental barriers in terms of accessibility problem detection were identified. This represented a preliminary version of an accessibility screening tool, which can be efficient for research and policy interventions focusing on accessibility. …
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Pattern of recovery and outcome after stroke in patients accessing a Western Cape rehabilitation facility
… and work status at six months, as well as environmental features. Procedure: Patients who met the eligibility criteria were assessed at admission discharge and six months post stroke. Data Analysis: Summary statistics were used to present descriptive data. Friedmans analysis of variance and …
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Powered mobility device use: participation and accessibility
… problems in terms of accessibility in various environmental arenas that have an impact on mobility. An additional important contribution is that the results show that the experiences of users of powered mobility devices should be taken seriously as they convey different aspects of how the use …